This invention relates to a bearing arrangement for a rotatable turning bar.
Surfacing machines which are mounted within a workpiece, such as a large valve or the like, typically cannot accurately repeat a given mount. This is critical when the operator must mount and dismount the machine to change surfacing tools in the course of a surfacing operation. Initially, the machine is mounted and aligned relative to a portion of the workpiece to be surfaced and a cutting operation is performed. The machine is then dismounted in order to attach a grinding tool and remounted, as close to the initial mount as possible, to perform a grinding operation. Misalignment relative to the initial mounting requires that the grinding operation first work the surface to conform to the new mounting alignment. The net result is that an excessive amount of material is removed due to an inability to replicate the initial mount. Many prior art devices require special mounting surfaces integral to the work site, i.e. the workpiece, and are often limited to special surfacing operations, such as valve seat resurfacing.